Credit/debt isn't really a huge issue, it's more our comfort level.

Something that also does online applications and credit checks etc?

be mindful in a C- / D neighborhood, that fancy gadgets and gizmos may draw the attention of the neighborhood miscreants because they know when a board-up is being worked on that new items are being added inside...sounds like a great security system is needed and make a friend with a nosey neighbor, leave your card with contact info on it to keep you in the know of potential shady goings-on with the property.  

You could even ask them for several business cards and tell them you will distribute them to potential buyers. 

Our board’s mandate a new census card (sheet with current info of residents (tenant or owner)) be submitted each year and whenever there is a change.

The mortgage guys really hurting are the ones that built their practice on the low hanging fruit house of cards of artificially low rates, which is rate and term refinance business from a call center cubicle thingie.

The SDIRA is responsible for all credits and debits incurred by the investment. 

But I recall Fannie Mae backed loans having a base DTI of 36% and it can go up to 45% if you meet credit score and reserve requirements.

You will still be able to dictate who you rent to based on credit score, criminal background, landlord references, work history etc..

I have very good credit so I’m not worried that I wouldn’t get a mortgage.